Role ofHLA,KIR,MICA, and Cytokines Genes in Leprosy

Abstract

Many genes includingHLA,KIR, andMICAgenes, as well as polymorphisms in cytokines have been investigated for their role in infectious disease.HLAalleles may influence not only susceptibility or resistance to leprosy, but also the course of the disease. Some combinations ofHLAandKIRmay result in negative as well as positive interactions between NK cells and infected host cells withM. leprae, resulting in activation or inhibition of NK cells and, consequently, in death of bacillus. In addition, studies have demonstrated the influence ofMICAgenes in the pathogenesis of leprosy. Specifically, they may play a role in the interaction between NK cells and infected cells. Finally, pro- and anti-inflammatory cytokines have been influencing the clinical course of leprosy. Data from a wide variety of sources support the existence of genetic factors influencing the leprosy pathogenesis. These sources include twin studies, segregation analyses, family-based linkage and association studies, candidate gene association studies, and, most recently, genome-wide association studies (GWAS). The purpose of this brief review was to highlight the importance of some immune response genes and their correlation with the clinical forms of leprosy, as well as their implications for disease resistance and susceptibility.